Electrostatic chuck design for cooling-gas light-up prevention

Abstract

An Electrostatic Chuck (ESC) in a chamber of a semiconductor manufacturing apparatus is presented for eliminating cooling-gas light-up. One wafer support includes a baseplate connected to a radiofrequency power source, a dielectric block, gas supply channels for cooling the wafer bottom, and first and second electrodes. The dielectric block is situated above the baseplate and supports the wafer when present. The first electrode is embedded in the top half of the dielectric block, where the top surface of the first electrode is substantially parallel to a top surface of the dielectric block, and the first electrode is connected to a DC power source. Further, the second electrode is embedded in a bottom half of the dielectric block, the second electrode being electrically connected to the first electrode, where the bottom surface of the second electrode is substantially parallel to a top surface of the baseplate.

Description

BACKGROUND1. Field of the Invention[0001]The present embodiments relate to systems, methods, and programs for improving the design of an Electrostatic Chuck (ESC), and more particularly, for eliminating cooling-gas light-up within the ESC.2. Description of the Related Art[0002]Some new semiconductor manufacturing processes utilize very high radio frequency (RF) power to generate plasma. The high RF power increases the RF currents and total voltages applied to the Electrostatic Chuck (ESC), also referred to herein as chuck or wafer susceptor, when compared to previous solutions with lower RF power levels.[0003]In addition, some new plasma etch processes require significantly lower RF frequencies (e.g., 2 MHz or lower) than previously utilized. The lower RF frequencies cause an increase in the RF voltage applied across the ESC ceramic. The high voltage applied across the ceramic may cause electrical discharge (i.e., arcing) between the wafer and the baseplate, and may cause ignition o...

AI Technical Summary

Benefits of technology

This solution effectively reduces the probability of arcing and light-up, improving chamber uptime and yield while decreasing manufacturer costs by lowering the voltage across the ceramic, thus enhancing the reliability and longevity of ESCs.

Problems solved by technology

The high voltage applied across the ceramic may cause electrical discharge (i.e., arcing) between the wafer and the baseplate, and may cause ignition of the heat transfer gas (e.g., He) in the gas supplying holes.

Arcing in the ESC may cause damage to the ESC and / or damage to other chamber components.

Further, such arcing may in some cases cause interruption of the manufacturing process.

Sometimes the destruction of the ESC is fast, catastrophic, and easily detected, but other times there is a gradual deterioration that may unknowingly affect multiple wafers, and the damage to the wafers may only be detectable at later steps of the manufacturing process.

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